Heat sink



FIG. 1 is a top view of a heat sink showing our new design;

FIG. 2 is a side perspective view thereof;

FIG. 3 is a side perspective view thereof taken from the side oppositethat shown in FIG. 2;

FIG. 4 is an end view thereof;

FIG. 5 is a side view thereof;

FIG. 6 is an end view thereof from the end opposite that shown in FIG.4;

FIG. 7 is a side view thereof taken from the side opposite that shown inFIG. 5; and,

FIG. 8 is a bottom view thereof.

The ornamental design for a heat sink, as shown and described.